Myogenic, mechanical and structural characteristics of resistance arterioles from healthy and ischaemic subjects

2003 ◽  
Vol 105 (6) ◽  
pp. 683-689 ◽  
Author(s):  
P. COATS
Keyword(s):  
Mechanical Properties ◽  
Internal Control ◽  
Regional Blood Flow ◽  
Structural Characteristics ◽  
Critical Limb Ischaemia ◽  
Myogenic Tone ◽  
Limb Ischaemia ◽  
Active Pressure ◽  
Chemical Stimuli ◽  
And Function

In critical limb ischaemia (CLI), the ability to regulate regional blood flow in the diseased portion of the leg would appear to be severely compromised. Considering this, pressure-dependent myogenic and mechanical properties of resistance arterioles isolated from control subjects and from patients with CLI were studied. Using confocal microscopy and pressure myography, subcutaneous resistance arteriole structure and function were compared between subcutaneous arterioles isolated from healthy volunteers [control subcutaneous (CS)] and non-diseased proximal subcutaneous (PS; internal control) and distal subcutaneous (DS) arterioles from the diseased ischaemic part of the limb from patients with CLI. Significant wall atrophy was observed in DS arterioles compared with PS and CS arterioles. Passive pressure-dependent mechanical properties were significantly altered in the diseased arterioles compared with PS and CS arterioles. Active pressure-dependent myogenic tone was completely absent in DS arterioles. The atrophic structural remodelling in DS arterioles were correlated with the changes in vascular mechanics, but not with the ability of these arterioles to contract in response to chemical stimuli. However, active pressure-dependent myogenic tone was absent in the DS arterioles. The combination of altered pressure-dependent passive mechanical and active myogenic tone goes some way in explaining CLI sequelae and poor outcome following surgical revascularization experienced by these patients.

Altered small artery morphology and reactivity in critical limb ischaemia

1999 ◽  
Vol 96 (2) ◽  
pp. 155-163 ◽  
Author(s):  
C. HILLIER ◽  
R. D. SAYERS ◽  
P. A. C. WATT ◽  
R. NAYLOR ◽  
P. R. F. BELL ◽  
...  
Keyword(s):  
Sodium Nitroprusside ◽  
Vessel Wall ◽  
Structure And Function ◽  
Critical Limb Ischaemia ◽  
Limb Ischaemia ◽  
Small Arteries ◽  
Significant Impairment ◽  
And Function ◽  
Revascularization Procedures ◽  
Wall Contraction

Although the pathophysiology of critical limb ischaemia is poorly understood, there is evidence that the condition of the small arteries may determine the outcome of revascularization procedures. This study was designed to investigate the effects of critical limb ischaemia on the structure and function of the small arteries in the leg. Small arteries (< 500 μm) from proximal (non-ischaemic) and distal (ischaemic) sites were obtained from patients undergoing bypass surgery for critical limb ischaemia and mounted in a myograph. Reactivity and morphological measurements were carried out and compared with controls. Control vessels from the thigh and calf showed no difference in media to lumen ratio. However, a comparison of ischaemic and non-ischaemic vessels from the patients with critical limb ischaemia showed significant thinning of the ischaemic vessel wall. Contraction studies using noradrenaline and angiotensin II revealed a significant decrease in the response of ischaemic vessels compared with the non-ischaemic vessels from the same patient. Moreover, these differences in reactivity were still apparent after the responses were corrected for wall thickness. Endothelial function assessed using the endothelium-dependent agonists acetylcholine and bradykinin showed a significantly impaired relaxation response to acetylcholine but not to bradykinin in the ischaemic vessels, and acetylcholine-induced relaxation was not improved after incubation with indomethacin. There was no change in the response to the endothelium-independent cAMP-mediated vasodilator iloprost but a significant impairment to sodium nitroprusside which acts via cGMP. These results suggest that small arteries in critical limb ischaemia are altered in both structure and function, with vessel wall thinning and impaired responses to acetylcholine and sodium nitroprusside.

Critical limb ischaemia in diabetes: definition, assessment, prognosis

VASA ◽  
2001 ◽  
Vol 30 (Supplement 58) ◽  
pp. 21-27
Author(s):  
Luther
Keyword(s):  
Diabetic Foot ◽  
Laboratory Tests ◽  
Critical Limb Ischaemia ◽  
Limb Ischaemia ◽  
Clinical Use ◽  
Arterial Reconstruction ◽  
Arterial Circulation ◽  
Diabetic Foot Disease ◽  
Foot Disease ◽  
Fontaine Classification

In diabetic foot disease, critical limb ischaemia (CLI) cannot be precisely described using established definitions. For clinical use, the Fontaine classification complemented with any objective verification of a reduced arterial circulation is sufficient for decision making. For scientific purposes, objective measurement criteria should be reported. Assessment of CLI should rely on the physical examination of the limb arteries, complemented by laboratory tests like the shape of the PVR curve at ankle or toe levels, and arteriography. The prognosis of CLI in diabetic foot disease depends on the success of arterial reconstruction. The best prognosis for the patients is with a preserved limb. Reconstructive surgery is the best choice for the majority of patients.

Comparison of one-year prognosis of patients classified as chronic critical lower limb ischaemia according to TASC II or European consensus definition in the COPART cohort

VASA ◽  
2015 ◽  
Vol 44 (3) ◽  
pp. 0220-0228 ◽  
Author(s):  
Marion Vircoulon ◽  
Carine Boulon ◽  
Ileana Desormais ◽  
Philippe Lacroix ◽  
Victor Aboyans ◽  
...  
Keyword(s):  
Medical Treatment ◽  
Critical Limb Ischaemia ◽  
Limb Ischaemia ◽  
Medical Group ◽  
Consensus Definition ◽  
Transcutaneous Oxygen ◽  
European Consensus ◽  
Group A ◽  
One Year ◽  
Group B

Background: We compared one-year amputation and survival rates in patients fulfilling 1991 European consensus critical limb ischaemia (CLI) definition to those clas, sified as CLI by TASC II but not European consensus (EC) definition. Patients and methods: Patients were selected from the COPART cohort of hospitalized patients with peripheral occlusive arterial disease suffering from lower extremity rest pain or ulcer and who completed one-year follow-up. Ankle and toe systolic pressures and transcutaneous oxygen pressure were measured. The patients were classified into two groups: those who could benefit from revascularization and those who could not (medical group). Within these groups, patients were separated into those who had CLI according to the European consensus definition (EC + TASC II: group A if revascularization, group C if medical treatment) and those who had no CLI by the European definition but who had CLI according to the TASC II definition (TASC: group B if revascularization and D if medical treatment). Results: 471 patients were included in the study (236 in the surgical group, 235 in the medical group). There was no difference according to the CLI definition for survival or cardiovascular event-free survival. However, major amputations were more frequent in group A than in group B (25 vs 12 %, p = 0.046) and in group C than in group D (38 vs 20 %, p = 0.004). Conclusions: Major amputation is twice as frequent in patients with CLI according to the historical European consensus definition than in those classified to the TASC II definition but not the EC. Caution is required when comparing results of recent series to historical controls. The TASC II definition of CLI is too wide to compare patients from clinical trials so we suggest separating these patients into two different stages: permanent (TASC II but not EC definition) and critical ischaemia (TASC II and EC definition).

Vascular trauma of the hand – a systematic review

VASA ◽  
2019 ◽  
Vol 48 (3) ◽  
pp. 205-215 ◽  
Author(s):  
Uwe Wahl ◽  
Ingmar Kaden ◽  
Andreas Köhler ◽  
Tobias Hirsch
Keyword(s):  
Duplex Sonography ◽  
Vascular Trauma ◽  
Vascular Lesions ◽  
Critical Limb Ischaemia ◽  
Limb Ischaemia ◽  
Limited Information ◽  
Endovascular Interventions ◽  
Provocation Tests ◽  
Objective Basis ◽  
Allen Test

Abstract. Hypothenar or thenar hammer syndrome (HHS) and hand-arm vibration syndrome (HAVS) are diseases caused by acute or chronic trauma to the upper extremities. Since both diseases are generally related to occupation and are recognised as occupational diseases in most countries, vascular physicians need to be able to distinguish between the two entities and differentiate them from other diagnoses. A total of 867 articles were identified as part of an Internet search on PubMed and in non-listed occupational journals. For the analysis we included 119 entries on HHS as well as 101 papers on HAVS. A professional history and a job analysis were key components when surveying the patient’s medical history. The Doppler-Allen test, duplex sonography and optical acral pulse oscillometry were suitable for finding an objective basis for the clinical tests. In the case of HHS, digital subtraction angiography was used to confirm the diagnosis and plan treatment. Radiological tomographic techniques provided very limited information distal to the wrist. The vascular component of HAVS proved to be strongly dependent on temperature and had to be differentiated from the various other causes of secondary Raynaud’s phenomenon. The disease was medicated with anticoagulants and vasoactive substances. If these were not effective, a bypass was performed in addition to various endovascular interventions, especially in the case of HHS. Despite the relatively large number of people exposed, trauma-induced circulatory disorders of the hands can be observed in a comparatively small number of cases. For the diagnosis of HHS, the morphological detection of vascular lesions through imaging is essential since the disorder can be accompanied by critical limb ischaemia, which may require bypass surgery. In the case of HAVS, vascular and sensoneurological pathologies must be objectified through provocation tests. The main therapeutic approach to HAVS is preventing exposure.

Overview of Treatment Options for Critical Limb Ischaemia Patients

2011 ◽  
Vol 7 (1) ◽  
pp. 51 ◽  
Author(s):  
Frederic Baumann ◽  
Nicolas Diehm ◽  
◽  
Keyword(s):  
Treatment Options ◽  
Critical Limb Ischaemia ◽  
Treatment Modalities ◽  
High Morbidity ◽  
Limb Ischaemia ◽  
Arterial Revascularisation ◽  
Planning Treatment ◽  
Treatment Concepts ◽  
Peripheral Arterial ◽  
Renal Origin

Patients with critical limb ischaemia (CLI) constitute a subgroup of patients with particularly severe peripheral arterial occlusive disease (PAD). Treatment modalities for these patients that often exhibit multilevel lesions and severe vascular calcifications are complicated due to multiple comorbidities, i.e. of cardiac and vascular but also of renal origin. These need to be taken into consideration while planning treatment options. Although CLI is associated with considerably high morbidity and mortality rates, the clinical outcome of patients being subjected to revascularisation has improved substantially in recent years. This is mainly due to improved secondary prevention strategies as well as dedicated endovascular innovations for this most challenging patient cohort. The aim of this article is to provide a discussion of the contemporary treatment concepts for CLI patients with a focus on arterial revascularisation.

scholarly journals One-year outcomes of drug-coated balloon treatment for long femoropopliteal lesions: a multicentre cohort and real-world study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xiaoxi Yu ◽  
Xin Zhang ◽  
Zhichao Lai ◽  
Jiang Shao ◽  
Rong Zeng ◽  
...  
Keyword(s):  
Real World ◽  
Cox Regression ◽  
Ankle Brachial Index ◽  
Primary Patency ◽  
Critical Limb Ischaemia ◽  
Limb Ischaemia ◽  
Cox Regression Analysis ◽  
Femoropopliteal Artery ◽  
Kaplan Meier ◽  
Multicentre Cohort

Abstract Background Drug-coated balloons (DCBs) have shown superiority in the endovascular treatment of short femoropopliteal artery disease. Few studies have focused on outcomes in long lesions. This study aimed to evaluate the safety and effectiveness of Orchid® DCBs in long lesions over 1 year of follow-up. Methods This study is a multicentre cohort and real-world study. The patients had lesions longer than or equal to 150 mm of the femoropopliteal artery and were revascularized with DCBs. The primary endpoints were primary patency, freedom from clinically driven target lesion revascularization (TLR) at 12 months and major adverse events (all-cause death and major target limb amputation). The secondary endpoints were the changes in Rutherford classification and the ankle brachial index (ABI). Results One hundred fifteen lesions in 109 patients (mean age 67 ± 11 years, male proportion 71.6%) were included in this study. The mean lesion length was 252.3 ± 55.4 mm, and 78.3% of the lesions were chronic total occlusion (CTO). Primary patency by Kaplan–Meier estimation was 98.1% at 6 months and 82.1% at 12 months. The rate of freedom from TLR by Kaplan–Meier estimation was 88.4% through 12 months. There were no procedure- or device-related deaths through 12 months. The rate of all-cause death was 2.8%. Cox regression analysis suggested that renal failure and critical limb ischaemia (CLI) were statistically significant predictors of the primary patency endpoint. Conclusion In our real-world study, DCBs were safe and effective when used in long femoropopliteal lesions, and the primary patency rate at 12 months by Kaplan–Meier estimation was 82.1%.

scholarly journals Fabrication of Polycaprolactone/Nano Hydroxyapatite (PCL/nHA) 3D Scaffold with Enhanced In Vitro Cell Response via Design for Additive Manufacturing (DfAM)

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1394
Author(s):  
Yong Sang Cho ◽  
So-Jung Gwak ◽  
Young-Sam Cho
Keyword(s):  
Mechanical Properties ◽  
Cell Response ◽  
Structural Characteristics ◽  
Structure Design ◽  
Compressive Modulus ◽  
Control Group ◽  
Design For Additive Manufacturing ◽  
3D Scaffold ◽  
3D Printed

In this study, we investigated the dual-pore kagome-structure design of a 3D-printed scaffold with enhanced in vitro cell response and compared the mechanical properties with 3D-printed scaffolds with conventional or offset patterns. The compressive modulus of the 3D-printed scaffold with the proposed design was found to resemble that of the 3D-printed scaffold with a conventional pattern at similar pore sizes despite higher porosity. Furthermore, the compressive modulus of the proposed scaffold surpassed that of the 3D-printed scaffold with conventional and offset patterns at similar porosities owing to the structural characteristics of the kagome structure. Regarding the in vitro cell response, cell adhesion, cell growth, and ALP concentration of the proposed scaffold for 14 days was superior to those of the control group scaffolds. Consequently, we found that the mechanical properties and in vitro cell response of the 3D-printed scaffold could be improved by kagome and dual-pore structures through DfAM. Moreover, we revealed that the dual-pore structure is effective for the in vitro cell response compared to the structures possessing conventional and offset patterns.

Structural characteristics and mechanical properties of Ti(Cr) films produced on Si substrate

2009 ◽  
Vol 517 (19) ◽  
pp. 5715-5721
Author(s):  
Fanhao Zeng ◽  
Xiang Xiong ◽  
Guodong Li ◽  
Boyun Huang
Keyword(s):  
Mechanical Properties ◽  
Structural Characteristics ◽  
Si Substrate
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